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Home > Genomics > Lesson 3: Extracting Strawberry DNA

Lesson 3: Extracting Strawberry DNA

A stylized white DNA double helix made of dots appears along the left edge of a blue background with a subtle grid pattern, leaving ample blank space on the right.

Prepare for lesson:

  1. Review video
  2. Supplies for each group:
    1. Dish soap
    2. ½ cup of water
    3. 2 plastic cups
    4. 1 coffee filter
    5. 1 sandwich bag
    6. 2 strawberries
    7. Coffee stirrer, skewer or chopsticks
    8. Salt
    9. Rubbing alcohol
    10. Measuring spoon

During the lesson (in small groups):

  1. One person will remove leaves on strawberries, add them to the bag and mash them into a pulp.
  2. Another person will make the lysis solution by mixing 1 teaspoon salt, 2 teaspoons soap and ½ cup water.
  3. Another person will add 2-3 teaspoons of the lysis solution into the bag of mashed strawberries.
  4. Have someone close the bag and mix up the contents of the bag, gently smashing up the strawberry mixture to make sure the lysis solution gets into the whole mixture.
  5. Have someone set up the coffee filter in the second clean and empty cup and add the strawberry mixture in the filter straining out the liquid from the strawberry mixture into the cup. 
  6. Gently squeeze the remaining liquid out of the filter.
  7. Add equal parts rubbing alcohol, also known as isopropyl alcohol, into the strawberry liquid. You’ll be adding about the same amount of rubbing alcohol as strawberry liquid. If you want to be exact, you can use the measuring spoons to measure the amount of strawberry liquid you have. Don’t mix or stir the alcohol as you add it.
  8. You’ll notice a clear layer form on top, that’s your strawberry DNA!
  9. Have someone gently tilt the cup and using the stirrer/skewer/chopsticks, you’ll be able to pick up the strawberry DNA